Spencer Heath Archive

Item 1797

Penned notes by Heath, prelude to a discussion of propeller design and manufacture.

No date

The American Propeller Company has been busy for two years with just two things — making the very best propellers that they know how and constantly experimenting and investigating, both practically and by theory to test every possible element of design which might lead to superior results. They have made a special study of the complex flow of the air about the blades of a propeller as a fan or blower and a yet more intimate study of the action of the propeller in flight. The original work of this Company was founded on the investigations of its President, Mr. Spencer Heath, who we believe was the first to approach the subject strictly from the standpoint of the action of the propeller under the conditions of flight, regardless of its action as a fan or blower, considering each section of the propeller blade as an aerofoil moving at a definite velocity through a winding or helical path at a definite angle of incidence to its winding line of flight. It is on this view of a propeller that nearly all of our work and investigations have rested.

The subject of the theory and practice of propeller design is most fascinating, with so many branches and ramifications that it would require a treatise, rather than a catalogue to set forth in detail what has been learned. Nothing interests us more and we take particular pleasure in discussing it from any standpoint, especially when the listener is intel­ligent and possessed of some elementary knowledge of aerodynamics.

We are going to make such brief discussion as we can here in two parts — first regarding form and dimensions and second, materials and methods of construction.